DTHY 372: Radiology interp

What is cortical bone?

The dense outer layer of bone; appears radiopaque.

What is cancellous bone?

Soft, spongy bone located between two layers of dense cortical bone; appears primarily radiolucent.

What is a process?

A marked prominence or projection of bone.

What is a ridge?

A linear prominence or projection of bone.

What is a spine?

A sharp, thornlike projection of bone.

What is a tubercle?

A small bump or nodule of bone.

What is a tuberosity?

A rounded prominence of bone.

What is a canal?

A tubelike passageway through bone containing nerves and blood vessels.

What is a foramen?

An opening or hole that permits passage of nerves and blood vessels.

What is a fossa?

A broad, shallow, scooped-out or depressed area.

What is a sinus?

A hollow space, cavity, or recess.

What is a septum?

A bony wall or partition that divides two spaces or cavities.

What is a suture?

An immovable joint representing a line of union between adjoining skull bones.

What is the incisive foramen?

An opening at the midline of the anterior hard palate directly posterior to the maxillary central incisors.

How does the incisive foramen appear radiographically?

As a small ovoid or round radiolucent area between the roots of the maxillary central incisors.

What are the superior foramina of the incisive canal?

Two tiny openings on the floor of the nasal cavity that join to form the incisive canal.

How do the superior foramina of the incisive canal appear?

Two small round radiolucencies superior to the apices of the maxillary central incisors.

What is the median palatal suture?

An immovable joint between the two palatine processes of the maxilla.

How does the median palatal suture appear?

As a thin radiolucent line between the maxillary central incisors.

What is the lateral fossa?

A smooth, depressed area between the maxillary canine and lateral incisor.

How does the lateral fossa appear?

As a radiolucent area between the maxillary canine and lateral incisor.

What is the nasal cavity?

A pear-shaped compartment of bone located superior to the maxilla.

How does the nasal cavity appear?

As a large radiolucent area above the maxillary incisors.

What is the nasal septum?

A vertical bony wall dividing the nasal cavity into right and left nasal fossae.

How does the nasal septum appear?

As a vertical radiopaque partition.

What is the floor of the nasal cavity?

A bony wall formed by the palatal processes of the maxilla and horizontal portions of the palatine bones.

How does the floor of the nasal cavity appear?

As a dense radiopaque band above the maxillary incisors.

What is the anterior nasal spine?

A sharp projection of the maxilla at the anterior-inferior portion of the nasal cavity.

How does the anterior nasal spine appear?

As a V-shaped radiopaque area.

What are the inferior nasal conchae?

Wafer-thin curved plates of bone extending from the lateral walls of the nasal cavity.

How do the inferior nasal conchae appear?

As a diffuse radiopaque mass or projection within the nasal cavity.

What is the maxillary sinus?

A paired cavity within the maxilla located above the maxillary premolar and molar teeth.

How does the maxillary sinus appear?

As a radiolucent area above the apices of the maxillary premolars and molars.

What are sinus septa?

Bony walls or partitions that appear to divide the maxillary sinus into compartments.

How do sinus septa appear?

As radiopaque lines within the maxillary sinus.

What are nutrient canals?

Tiny tubelike passageways through bone containing blood vessels and nerves.

How do nutrient canals in the maxillary sinus appear?

As a narrow radiolucent band bounded by two thin radiopaque lines.

What is the inverted Y?

The intersection of the maxillary sinus and nasal cavity.

How does the inverted Y appear?

As a radiopaque upside-down Y above the maxillary canine.

What is the maxillary tuberosity?

A rounded prominence extending posterior to the third molar region.

How does the maxillary tuberosity appear?

As a radiopaque bulge distal to the third molar region.

What is the hamulus?

A small hooklike projection extending from the medial pterygoid plate of the sphenoid bone.

How does the hamulus appear?

As a radiopaque hooklike projection posterior to the maxillary tuberosity.

What is the zygomatic process of the maxilla?

A bony projection of the maxilla that articulates with the zygoma.

How does the zygomatic process appear?

As a J- or U-shaped radiopacity superior to the maxillary first molar region.

What is the zygoma?

The cheekbone that articulates with the zygomatic process of the maxilla.

How does the zygoma appear?

As a diffuse radiopaque band extending posteriorly from the zygomatic process.

What are the three main parts of the mandible?

Ramus, body, and alveolar process.

What is the ramus?

The vertical portion of the mandible found posterior to the third molar.

What is the body of the mandible?

The horizontal U-shaped portion extending from ramus to ramus.

What is the alveolar process?

The portion of the mandible that encases and supports the teeth.

What are genial tubercles?

Tiny bumps of bone on the lingual aspect of the mandible.

How do genial tubercles appear?

As a ring-shaped radiopacity below the apices of the mandibular incisors.

What is the lingual foramen?

A tiny opening on the internal surface of the mandible.

How does the lingual foramen appear?

As a small radiolucent dot inferior to the mandibular incisor apices.

What are mandibular nutrient canals?

Tubelike passageways containing nerves and blood vessels supplying the teeth.

How do mandibular nutrient canals appear?

As vertical radiolucent lines, often in the anterior mandible.

What is the mental ridge?

A linear prominence of cortical bone on the external anterior mandible.

How does the mental ridge appear?

As a thick radiopaque band extending from the premolar to incisor region.

What is the mental fossa?

A scooped-out depressed area on the external anterior mandible.

How does the mental fossa appear?

As a radiolucent area above the mental ridge.

What is the mental foramen?

An opening on the external surface of the mandible in the premolar region.

How does the mental foramen appear?

As a small round or ovoid radiolucency near the apices of mandibular premolars.

What can the mental foramen be mistaken for?

A periapical lesion.

What is the mandibular canal?

A tubelike passageway traveling the length of the mandible containing the inferior alveolar nerve and blood vessels.

How does the mandibular canal appear?

As a radiolucent band outlined by two thin radiopaque lines.

What is the mylohyoid ridge?

A linear prominence on the internal surface of the mandible.

How does the mylohyoid ridge appear?

As a dense radiopaque band extending downward and forward from the molar region.

What is the external oblique ridge?

A linear prominence on the external surface of the mandibular body.

How does the external oblique ridge appear?

As a radiopaque band extending downward and forward from the anterior border of the ramus.

What is the coronoid process?

A marked prominence on the anterior ramus of the mandible.

How does the coronoid process appear on an image?

As a triangular radiopacity superimposed over or inferior to the maxillary tuberosity.

What is enamel?

The outermost radiopaque layer of the crown.

Which tooth structure is most radiopaque?

Enamel.

What is dentin?

The structure that comprises most of the tooth and is less radiopaque than enamel.

What is the DEJ?

The junction between dentin and enamel.

What is the pulp cavity?

The pulp chamber and pulp canals.

How does the pulp cavity appear?

Radiolucent.

What is the lamina dura?

The wall of the tooth socket made of dense cortical bone.

How does the lamina dura appear?

As a dense radiopaque line surrounding the root.

What is the alveolar crest?

The most coronal portion of alveolar bone between teeth.

How does the alveolar crest appear?

Radiopaque and normally 1.5–2.0 mm below the CEJ.

What is the periodontal ligament space?

The space between the tooth root and lamina dura.

How does the PDL space appear?

As a thin radiolucent line around the root.

How does the anterior alveolar crest normally appear?

Pointed and sharp with a dense radiopaque line.

How does the posterior alveolar crest normally appear?

Flat and smooth and less dense/radiopaque than the anterior crest.

When do primary teeth begin erupting?

Around 6 months of age.

By what age should all 20 primary teeth be erupted and functioning?

By age 3.

How many teeth are in the primary dentition?

20.

What is mixed dentition?

The period when both primary and permanent teeth are present, approximately ages 6–12.

What is the mastoid process?

A bony prominence posterior and inferior to the TMJ.

How does the mastoid process appear on a panoramic image?

As a large rounded radiopacity posterior and inferior to the TMJ.

What is the styloid process?

A long, pointed projection extending downward from the temporal bone.

How does the styloid process appear?

As a long radiopaque spine.

What is the external auditory meatus?

An opening in the temporal bone.

How does the external auditory meatus appear?

As a round or ovoid radiolucency.

What is the glenoid fossa?

A concave depressed area of the temporal bone.

How does the glenoid fossa appear?

As a concave radiopacity superior to the mandibular condyle.

What is the articular eminence?

A rounded projection anterior to the glenoid fossa.

What is the lateral pterygoid plate?

A thin wing-shaped bony extension of the sphenoid bone.